[求助]关于and的连接

因为手头上没有语法书，所以想找各位牛牛确认一下：

以下几个用and连接的句子，究竟哪几个是对的？

Mr. Wang worked and he heard music.

Mr. Wang worked, and he heard music.

Mr. Wang worked and heard music.

Mr. Wang worked ,and  heard music.

姑且不考虑句子的意思问题和简洁性问题，我只想知道and前后是否可以两个完整句子，and前可否有句号

谢先

Wang worked and he heard music肯定错

Wang worked, and he heard music.可以，但不如下个好。

Wang worked and heard music.正确

Wang worked ,and  heard music. 短的时候最好不要加逗号，当中间修饰成分很长时也许可以，为了避免歧义。

谢谢版主

辛苦了